but
I have also got some patches of cirrus which are coming
from a NW direction. Now if this was the first signs of the
front, then shouldn't they simply appear to be coming from the SW?



Not necessarily, Col. The advection of warm air from the SW means there
must be some form of upper ridge. Ahead of this, i.e. before the surface warm
front, the upper winds will be W'ly or even NW'ly. I have seen Ci moving thus
many times ahead of a Low. It also ties in well will the rule-of-thumb that
with advection of warm air the wind veers with height, and vice versa, though
this latter case is difficult to observe from the ground.

Tudor Hughes, Warlingham, Surrey.